30 Mar, 2010

1 commit

  • …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

02 Oct, 2009

1 commit


30 Jul, 2009

3 commits

  • Every so often, after code shuffles, I need to go through and unbitrot
    the Lguest Journey (see drivers/lguest/README). Since we now use RCU in
    a simple form in one place I took the opportunity to expand that explanation.

    Signed-off-by: Rusty Russell
    Cc: Ingo Molnar
    Cc: Paul McKenney

    Rusty Russell
     
  • I don't really notice it (except to begrudge the extra vertical
    space), but Ingo does. And he pointed out that one excuse of lguest
    is as a teaching tool, it should set a good example.

    Signed-off-by: Rusty Russell
    Cc: Ingo Molnar

    Rusty Russell
     
  • "new" was freed and then dereferenced. Also the return value wasn't being
    used so I modified the caller as well.

    Compile tested only. Found by smatch (http://repo.or.cz/w/smatch.git).

    regards,
    dan carpenter

    Signed-off-by: Dan Carpenter
    Signed-off-by: Rusty Russell

    Dan Carpenter
     

01 Jul, 2009

1 commit

  • Change the eventfd interface to de-couple the eventfd memory context, from
    the file pointer instance.

    Without such change, there is no clean way to racely free handle the
    POLLHUP event sent when the last instance of the file* goes away. Also,
    now the internal eventfd APIs are using the eventfd context instead of the
    file*.

    This patch is required by KVM's IRQfd code, which is still under
    development.

    Signed-off-by: Davide Libenzi
    Cc: Gregory Haskins
    Cc: Rusty Russell
    Cc: Benjamin LaHaise
    Cc: Avi Kivity
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Davide Libenzi
     

12 Jun, 2009

4 commits

  • We no longer need an efficient mechanism to force the Guest back into
    host userspace, as each device is serviced without bothering the main
    Guest process (aka. the Launcher).

    Signed-off-by: Rusty Russell

    Rusty Russell
     
  • Currently, when a Guest wants to perform I/O it calls LHCALL_NOTIFY with
    an address: the main Launcher process returns with this address, and figures
    out what device to run.

    A far nicer model is to let processes bind an eventfd to an address: if we
    find one, we simply signal the eventfd.

    Signed-off-by: Rusty Russell
    Cc: Davide Libenzi

    Rusty Russell
     
  • We currently only allow the Launcher process to send interrupts, but it
    as we already send interrupts from the hrtimer, it's a simple matter of
    extracting that code into a common set_interrupt routine.

    As we switch to a thread per virtqueue, this avoids a bottleneck through the
    main Launcher process.

    Signed-off-by: Rusty Russell

    Rusty Russell
     
  • The Launcher could be inside the Guest on another CPU; wake_up_process
    will do nothing because it is "running". kick_process will knock it
    back into our kernel in this case, otherwise we'll miss it until the
    next guest exit.

    Signed-off-by: Rusty Russell

    Rusty Russell
     

30 Jan, 2009

1 commit


30 Dec, 2008

1 commit


02 May, 2008

2 commits


31 Mar, 2008

1 commit


28 Mar, 2008

1 commit


11 Mar, 2008

1 commit


30 Jan, 2008

10 commits


15 Nov, 2007

1 commit


25 Oct, 2007

1 commit


23 Oct, 2007

6 commits

  • This patch gets rid of the old lguest host I/O infrastructure and
    replaces it with a single hypercall "LHCALL_NOTIFY" which takes an
    address.

    The main change is the removal of io.c: that mainly did inter-guest
    I/O, which virtio doesn't yet support.

    Signed-off-by: Rusty Russell

    Rusty Russell
     
  • 1) This allows us to get alot closer to booting bzImages.

    2) It means we don't have to know page_offset.

    3) The Guest needs to modify the boot pagetables to create the
    PAGE_OFFSET mapping before jumping to C code.

    4) guest_pa() walks the page tables rather than using page_offset.

    5) We don't use page_offset to figure out whether to emulate: it was
    always kinda quesationable, and won't work for instructions done
    before remapping (bzImage unpacking in particular).

    6) We still want the kernel address for tlb flushing: have the initial
    hypercall give us that, too.

    Signed-off-by: Rusty Russell

    Rusty Russell
     
  • Move setup_regs() to lguest_arch_setup_regs() in i386_core.c given
    that this is very architecture specific.

    Signed-off-by: Jes Sorensen
    Signed-off-by: Rusty Russell

    Jes Sorensen
     
  • Apply Clue 2x4 to lguest userlandkernel handling code and the
    lguest launcher. Pointers are not to be passed in u32's!

    Basic rule of thumb: Anything passing u32's back and forth should be
    passing unsigned longs to be portable to 64 bit archs.

    For those who forgotten already, I repeat: NO POINTERS IN u32!

    Signed-off-by: Jes Sorensen
    Signed-off-by: Rusty Russell

    Jes Sorensen
     
  • Back when we had all the Guest state in the switcher, we had a fixed
    array of them. This is no longer necessary.

    If we switch the network code to using random_ether_addr (46 bits is
    enough to avoid clashes), we can get rid of the concept of "guest id"
    altogether.

    Signed-off-by: Rusty Russell

    Rusty Russell
     
  • In order to avoid problematic special linking of the Launcher, we give
    the Host an offset: this means we can use any memory region in the
    Launcher as Guest memory rather than insisting on mmap() at 0.

    The result is quite pleasing: a number of casts are replaced with
    simple additions.

    Signed-off-by: Rusty Russell

    Rusty Russell
     

27 Jul, 2007

2 commits


20 Jul, 2007

1 commit

  • This is the code for the "lg.ko" module, which allows lguest guests to
    be launched.

    [akpm@linux-foundation.org: update for futex-new-private-futexes]
    [akpm@linux-foundation.org: build fix]
    [jmorris@namei.org: lguest: use hrtimers]
    [akpm@linux-foundation.org: x86_64 build fix]
    Signed-off-by: Rusty Russell
    Cc: Andi Kleen
    Cc: Eric Dumazet
    Cc: Thomas Gleixner
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Rusty Russell